Kennedy, Vietnam and Ngo Dien Diem

In 1961, France's Charles de Gaulle told President John F. Kennedy that in
Vietnam the US would sink "step by step into a bottomless quagmire," however
much it spent "in men and money." Kennedy had begun sending more advisors
to Vietnam to help the Diem regime, increasing their number that year to 800.
Kennedy's military advisors told him he should send combat divisions to Vietnam. Kennedy refused, but he increased material aid to the regime. He used Truman's aid to Greece as a model. Truman had sent aid but no US combat troops and the Leftist rebels in Greece had been halted. But it was a bad analogy: South Vietnam was not Greece in the 1940s.

The Kennedy administration was supporting the Diem regime in the southern half of Vietnam, and in the South against Diem was the National Liberation Front (NLF), also known as the Viet Cong. Many who joined the National Liberation Front were southerners who had resettled in the North after the Geneva Accords of 1954. Hanoi had given them military training and had sent them back to the South along the Ho Chi Minh trail.

The historian Mark Philip Bradley writes that the NLF was able to infiltrate as many as 80 percent of the strategic hamlets constructed by Diem's government. In the race for control over other areas in the countryside, Bradley writes:

The [National Liberation] Front targeted the most competent and the most corrupt local officials of the Diem government, killing some 6,000 officials in the early 1960s. As many as 25,000 civilians were also murdered in this period, suggesting that the NLF did not always carefully discriminate between its targets. But once in control of an area, the Front generally did significantly reduce its attacks on civilians. NLF assassinations fell by 80 percent between 1961 and 1965 as their control over rural southern Vietnam increased.

Kennedy was allowing US pilots to fly combat missions in South Vietnam, while the pilots pretended to be instructors,
and he supported counter-insurgency to overthrow the Communists in the North. Diem was not winning his war. Kennedy saw hearts and minds as part of the struggle and he said that the war would have to be won by the Vietnamese themselves, not by Americans.

According to Peter Beinart in his book The Icarus Syndome, Kennedy put politics above doing what was best regarding Vietnam. Kennedy told Senate Majority Leader Mike Mansfield:

If I tried to pull out completely now from Vietnam, we would have another Joe McCarthy red scare on our hands, but I can do it after I'm reelected. (Beinart, p. 160)

To a friend, Charlie Bartlett, Kennedy said:

Those people [the Vietnamese] hate us. They are going to throw our asses out of there at almost any point. But I can't give up a piece of territory like that to the Communists and then get the American people to reelect me. (Beinart, p. 160)

Kennedy watched as Diem's
reign become more hated by people in the southern half of Vietnam. The Diem
family was Roman Catholic and had come into conflict with Buddhists – a large segment of the
South's population. In the city of Hué, Catholics had been permitted to fly
the papal banner, but the Buddhists had been prohibited from raising their flag.
In May 1963 thousands of Buddhists in Hué staged a protest demonstration. The
Diem regime sent troops in armored vehicles against them, and nine of the Buddhists
were killed. Diem accused the Buddhists of being Communist
sympathizers, and
in the weeks to come clashes took place between Diem's troops and anti-Diem
Buddhists. Buddhist monks began setting themselves afire, creating a sensation
around the world, while Diem's sister-in-law, Madame Nhu, described the burnings
as a Buddhist barbecue. Then, in August, Diem ordered troops loyal to him to
attack Buddhist temples in Hué, Saigon and other cities
in the south.

The Kennedy administration was aware of Diem's lack of popularity. He had given up the idea
that Diem would be able to rally the South in the fight against the Communists.
The Kennedy administration wanted an alternative to Diem. With US
connivance the Diem regime was overthrown by its military generals. Diem was assassinated,
and in the South people erupted in joy. People in the South's primary city, Saigon, bedecked army tanks
with flowers and paraded joyously through the streets.